This week’s conditioning is all about threshold work — riding hard at the edge of what you can sustain. You’ve spent the last two weeks building density and volume; now it’s time to see what that engine can actually hold. Four rounds of 3 minutes hard, 1 minute easy on the bike or row will push your aerobic power and teach you how to maintain pace under fatigue. The hard intervals should feel challenging but repeatable, not all-out sprints — the goal is controlled effort, consistent output, and learning where your threshold sits. Use the easy minutes to reset, then attack the next round with the same focus. This is your engine tune-up: push smart, stay honest, and leave the work knowing you’ve grown your capacity for controlled power.